1. Field of the Invention
The present invention relates to a seat for supporting an occupant of a vehicle and absorbing a force between the occupant and the vehicle created by relative movement between the occupant and the vehicle.
2. Description of the Related Art
Vehicles are widely used for military purposes, especially in recent military conflicts, to transfer soldiers, to enter combat areas, to patrol areas, etc. Such vehicles can be exposed to blasts resulting from an explosive such as an improvised explosive device, a mine, a grenade, etc. Forces from such blasts are transferred through the vehicle to the occupants. The vibration and/or reverberation of the blast through the vehicle can injure the occupants.
These vehicles can be armored to shield the occupants from such blasts but the armor of the armored vehicle is designed to remain rigid during a blast to deflect the blast and preserve the structural integrity of the vehicle, or at least the portion of the vehicle housing occupants. Unlike civilian automobiles that are designed to crush to absorb forces resulting from an automobile crash, the armor on the armored vehicle, due to its rigidity, does not crush and thus does not absorb forces resulting from the blast. As such, although the armor protects the occupants by maintaining structural rigidity of the vehicle, the blast vibrates and/or reverberates through the vehicle because the armor does not deform to absorb the energy of the blast. This vibration and/or reverberation through the vehicle can injure the occupant. For example, if the blast originates below the vehicle, the blast can vibrate and/or reverberate through the floor of the vehicle. In such a scenario, the occupant can be harmed if this vibration and/or reverberation is transferred directly to the occupant through the floor and/or the seat.
Further, whether the vehicle is armored or not, much of the technology for absorbing energy in a civilian automobile during an automobile accident is not suitable for absorbing energy from an explosive blast. As one example, conventional civilian automobiles are equipped with airbags that inflate upon crash of the automobile. The airbag can inflate within 5 milliseconds. Due to the speeds of typical civilian automobile accidents and/or due to the crushing of the automobile to absorb energy, the immediate need for inflation of the airbag is not necessary and the 5 millisecond delay is acceptable. In other words, in a civilian automobile accident, the inflation of the airbag is not needed earlier than 5 milliseconds after the crash. However, in the case of an explosive blast, the magnitude of the blast can be such that the forces of the blast are almost instantaneously transferred to the occupant, i.e., forces that can harm the occupant are transferred through the armored vehicle in less than 5 milliseconds. Further, in the case of an armored vehicle, for example, the armor is relatively rigid and does not absorb much, if any, forces. As such, much or all of the force resulting from the blast is transferred virtually instantaneously through the vehicle to the occupant. As such, the airbags used in civilian automobiles cannot react quickly enough due to the 5 millisecond delay associated with the civilian automobile airbags.
In addition to generating initial forces acting on the vehicle, the blast can also cause the vehicle to become airborne. The occupant can suffer injuries relating to the landing of the vehicle on the ground, i.e., the “slam down.”